A variety of techniques are currently used for the creation and manipulation of video post-production effects. One common technique involves the use of chroma key compositing, which composites (layers) two or more images or video streams based on color hues. A well-known example of this type of video effect is used in many television news productions, which superimpose a human presenter who is captured in front of a chroma key screen (e.g., a “green screen”) over a computer-generated weather map or other computer-generated content. Another common technique for compositing involves the use of visible background subtraction, which is performed after calculating the color distance between a known background image and an input video stream. With the background content removed, the video stream can then be composited with other video content.
These and similar video compositing techniques involve the use and processing of visible information to identify the boundaries between desired and undesired video content. Unfortunately, the effects from such composting techniques may be distorted or unreliable during uneven lighting or incorrect camera exposure conditions. These compositing techniques are also imprecise and often experience difficulty in tracking movement. As a result, chroma key compositing and background subtraction are unable to be cleanly used in many low-light and real world settings.
Limited techniques have been proposed for the use of infrared video compositing to segment video content without being restricted by the limitations of visible light as described above. For instance, a 1960 paper published by Zoli Vidor, “An Infrared Self-Matting Process”, discusses the use of compositing through an infrared traveling matte process, provided from visible and infrared light exposures captured on separate sets of film. The applicability of the Vidor technique, however, is limited due to the use of a specialized camera and the complexity of film-based processing. A more recent example, a 2002 paper published by Paul Debevec et al., “A Lighting Reproduction Approach to Live-Action Compositing”, discusses the use of live-action matting and compositing with digital video with use of near-infrared light. However, the Debevec paper emphasizes the use of a near-infrared camera within a specialized light stage for the purpose of replicating lighting special effects from complex motion picture scenes. As a result, infrared video compositing has only been applied in limited settings, such as in complex and artificial video capture stages or research environments.